KR20010070345A - Driving apparatus for sewing machine - Google Patents

Abstract

PURPOSE: To provide a sewing machine which can make friction contact parts oilless and enables the reduction of manufacturing load and weight. CONSTITUTION: Friction surfaces which come into contact, under friction, with the sewing machine 10, and make sliding movement and rotating movement at a high speed under high load are constituted by using rice bran ceramics. For example, a bearing 100 relating to a shaft and bearing constituting the drive section of the sewing machine 1 is formed as a bearing formed by fitting and fixing pushing-like molded articles 102 consisting of the rice bran ceramics into a housing member 101 which constitute the outer frame of the bearing 100 and consists of metal. According to the constitution described above, the inside surfaces 102A which are the friction surfaces of the flanks of the shaft and the bearing 100 are formed of the rice bran ceramics having a small coefficient of friction, by which these parts may be made oilless.

Description

Sewing machine moving device {DRIVING APPARATUS FOR SEWING MACHINE}

The present invention relates to a sewing machine capable of lubricating oil-free components of sliding rotation.

The driving part of the conventional industrial sewing machine composed of many parts which frictionally contact each other while sliding movement or rotation movement under high speed and high load mainly consists of a rotating shaft and a bearing. Therefore, the structure of the rotating shaft and the bearing has a structure that injects lubricating oil so as not to cause fretting wear, for example, because a combination of metal materials generally causes crushing or abnormal wear between the metal materials. many.

In the industrial sewing machine, the parts to be contacted and ruined deteriorate due to the heat generated by the friction, so it is necessary to provide a lubricating oil to forcibly supply the lubricating oil in order to supply the lubricating oil. As the lubrication device, for example, an oil supply pipe for supplying lubricating oil to the contact portion, an oil pan for storing lubricating oil, a pump for sucking up lubricating oil, and the like are provided. In such a structure, a lubricating oil is sucked up by a pump from an oil container, and it circulates to each contact part through an oil pipe.

In addition, the wear caused by the sliding movement and the rotation movement or the resistance caused by the sliding movement and the rotation movement is determined by the sliding and rotation movement speed and the load applied during the sliding / rotation movement, that is, the surface pressure. It depends greatly on the PV value. That is, the faster the speed, and the greater the surface pressure, the higher the friction rate, the greater the frictional resistance and the greater the wear.

Therefore, in the above-mentioned sewing machine having a structure for supplying lubricating oil to the contact / friction part, for example, when the lubricating oil supply amount is excessive, the needle take-up lever is also used when the upper and lower reciprocating movements of the needle bar operate at high speed. When the up lever) swings and the needle bar crank rod rotates, there is a risk that the lubricant splashes around and the lubricant leaks out of the sewing machine and contaminates the sewing material.

On the contrary, when the supply amount of the lubricating oil is insufficient, there is a risk of abnormal wear or sticking of the contact portion.

In addition, as described above, when the lubricating oil supply unit is installed in the contact portion, the number of parts of the sewing machine increases, so that not only the manufacturing load and the production cost increase, but also the weight of the sewing machine increases, thus, the lubrication free of the contact / friction portion of the sewing machine. The need for anger was raised.

Therefore, in order to realize lubrication-free, the surface of the metal material forming the friction surface of the contact portion is coated to form a ceramic film such as, for example, tin (TiN), diamondized carbon (DLC), MOS2 for lubrication, and the like. Teflon coating treatment or a structure using a wear resistant resin material or CFRP (carbon fiber reinforced resin) was attempted.

However, the above-described coating treatment of the metal material surface may lose the coating effect due to wear or peeling of the coating layer when used for a long time. In addition, conventional wear-resistant resin materials have a large coefficient of thermal expansion, which sometimes causes large deformation due to heat generated by sliding or rotational frictional motion. In addition, the conventional wear-resistant resin material is often a study required for processing in order to obtain a satisfactory dimensional accuracy, it is also a material that is easy to wear.

Therefore, as described above, lubrication of the sliding friction portion of the industrial sewing machine could not be fully realized.

The present invention has been made in consideration of the above technical state, and an object of the present invention is to provide a sewing machine capable of achieving lubrication of the contact portion, and at the same time reducing the manufacturing load and reducing the weight.

The sewing machine described in claim 1 is a contacting part of at least one component in a sewing machine 10 equipped with components which come into contact with each other by friction and sliding movement, for example, as illustrated in FIG. It is characterized by consisting of this hard porous carbon material.

According to such a structure, the hard porous carbon material has a small coefficient of friction, so that not only the amount of wear is reduced when the parts are in contact with each other but also the heat generation can be suppressed small. Therefore, the lubrication of the sewing machine can be achieved by improving the wear resistance and the adhesion resistance of the contact portion.

In addition, since it is not necessary to inject lubricating oil into the contact portion, it is not necessary to provide oil supply means such as an oil supply pipe, an oil container, an oil pump for supplying lubricating oil, and the weight of the sewing machine can be reduced.

In addition, the parts of the contact portion is made of a hard porous carbon material having a lower density than the metal material, further contributing to the weight reduction.

In addition, since it is not necessary to supply a lubricating oil supply, it is possible to reduce the number of parts of the sewing machine, not only to reduce the manufacturing process, but also to reduce the manufacturing cost.

Further, the contact frictional motion includes a sliding motion in a straight line along the axial direction of the axis, and a rotational motion accompanied by the rotational motion of the axis, or the sliding motion.

In addition, a bearing structure having a cylindrical inner cylinder portion into which a circumferential shaft for sliding motion, rotational movement, or a combination of both is inserted in the axial direction, and an axis having an arbitrary cross-sectional shape, It may include a structure for performing a linear sliding movement in the longitudinal direction by inserting into the bearing having an inner cylinder portion of the shape matching the cross-sectional shape.

Further, the structure described in claim 1, for example, a bearing (needle bar upper metal 19A and lower metal 19B) mounted on a swinging table, a take-up slide bearing, and various slides Application to bearings for rods can adequately achieve lubrication.

Further, for example, when the structure described in claim 1 is applied to the bearing, a bushing member made of a hard porous carbon material may be mounted and fixed inside the bearing shell. .

In addition, the contact portion includes, for example, a case in which the rectangular cam moves with contact friction along a groove formed to guide the motion of the rectangular cam, such as a rectangular cam mounted on a drive unit of the sewing machine. In this case, lubrication can be excellently achieved by forming the friction surface portion of the square cam and the groove with a hard porous carbon material.

In addition, it is possible to reduce the amount of oil supply by using a structure using the hard porous carbon material on the friction surface of the contact portion of the sewing machine and a structure injecting lubricant into the contact portion.

The part to be formed of the hard porous carbon material may be formed of only one of the friction surfaces of the parts in contact with each other by the hard porous carbon material, or both surfaces may be formed of the hard porous carbon material.

In addition, a plurality of parts themselves in contact with each other may be formed of a hard porous carbon material.

Moreover, it can also be set as the structure which attaches and fixes the member formed from the hard porous carbon material to the friction surface of a metal component as a base material. At this time, in order to fix and fix the member formed of the hard porous carbon material to the said outer member, you may use an adhesive or mechanically fasten with a small screw, for example.

The hard porous carbon material is, for example, a step of forming a molded part from the mixed material using a mixed material containing at least a cellulose-based material and a resin, and a step of firing and carbonizing the molded part. It is prepared by a manufacturing method comprising a.

For example, degreasing steel which removes oil from rice bran produced in the process of refining brown rice and obtaining white rice is an excellent cellulose-based material. The degreasing steel is impregnated with resin and then compressed to form a molded article, followed by drying. The dried molded article thus produced is heat-treated in an inert gas, for example, nitrogen gas, to be produced by carbonization. This is the rice bran ceramics.

In this case, since it does not harm the natural environment even if it is disposed of after use, it is possible to secure abundant and stable raw materials (tangji steel) as an article excellent in environmental compatibility. In addition, the use of degreasing rivers can reduce the use of wood and contribute to the deforestation of forest resources worldwide.

In addition, in the production of the micro-ceramics, various resin materials which can be carbonized by heat treatment are used, and specifically, for example, thermosetting resins such as phenol resins are preferably used.

The hard porous carbon material obtained by the above-described manufacturing method can produce a molded article easily by, for example, using a mold or the like, or by applying various general-purpose processing such as extrusion and cutting. Therefore, the molded article of a complicated shape can be manufactured easily, and manufacturing cost can be suppressed at low cost.

In addition, the hard porous carbon material has a property that the hardness can be adjusted according to the firing temperature in the step of firing and carbonizing the molded article, so that the hard porous carbon material can be set to the hardness required by the part and fired.

In addition, since the porosity of the hard porous carbon material changes depending on the firing temperature, the rigid porous carbon material has a property of controlling density, so that a density consistent with the PV value use condition can be obtained.

In the sewing machine described in claim 2, one of the two components described above forms a metal annular portion, and an axial portion is formed so that the other component can be inserted into the annular portion. In this case, the contact surface of one component is formed of the hard porous carbon material.

According to the above structure, the contact surface serving as the friction surface is formed of a hard porous carbon material, and oil-free can be achieved as in claim 1.

In addition, the structure of the shaft portion and the annular portion, for example, as shown in Figure 1 can be applied to the structure of the shaft and the bearing constituting the drive unit of the sewing machine, it is possible to lubricate the contact portion of the shaft and the bearing.

In this case, the members forming the outer shell portion and the inner cylinder portion do not necessarily need to be formed of one member each, but can be constituted from a plurality of members.

In addition, as long as the member of the hard porous carbon material which forms an inner cylinder part can be fixed to the friction surface mentioned above, any shape, such as cylindrical shape and plate shape, is irrelevant.

The sewing machine according to claim 3 is characterized in that, in the sewing machine according to claim 1 or 2, the contact surface formed of the hard porous carbon material has a plurality of fine finishes due to the pores of the hard porous carbon material. .

According to such a structure, the wear powder which arises in an initial stage of abrasion wears into the fine fine part formed in the friction surface which at least two members contact and rub against each other. Thus, lubrication can be achieved because the wear powder that has entered the fine portion reduces the coefficient of friction (self-lubrication) that both members come into contact with each other / friction.

In addition, according to the above structure, since a large number of fine parts are formed by the pores of the hard porous carbon material on the friction surface, lubricating oil such as grease can be impregnated into the fine parts, for example, and the friction resistance and the adhesion resistance are further increased. This is improved.

In addition, as described above, the hard porous carbon material can change the density (porosity) in accordance with the manufacturing conditions. For example, in the case of a structure in which a hard porous carbon material having a large porosity is impregnated with a lubricant such as grease, a larger amount is required. Because the impregnated lubricant can be impregnated, wear resistance and adhesion resistance can be further improved.

In addition, since the hard porous carbon material is a so-called porous material, there are many pores therein. Therefore, even if the surface of the hard porous carbon material is worn, new pores therein may be exposed to form a large number of fine parts on the surface.

1 is an exploded perspective view of a drive part of a sewing machine 10 of a first example of the embodiment of the present invention.

2 is a side view of the driving unit of the sewing machine 10.

3 is an exploded perspective view of the sewing machine 20 as a modification of the first embodiment.

Figure 4 is a side view of the upper louver holder bearing that is the contact portion of the sewing machine.

Fig. 5 is a sectional view 4b of a bearing in which a bushing formed of microscopic ceramics is fixed to an inner surface of a bearing, and a diagram 4a illustrating a cross section of microscopic ceramics.

※ Explanation of symbols about main part of drawing ※

Needle attachment port (1A), male threaded shaft (1AA), sewing needle (1B),

Swing shaft metal (1C), inner cylinder (1CA), swing shaft (1D),

Sewing machine 10, upper shaft 11, upper shaft front metal (11A),

Inner cylinder portion 11Aa, counterweight 11B, insertion hole 11Ba,

Screw holes 11Bb, 11Bb, Bolts 11Bc, 11Bc, Connecting shaft 12

Cutting part 12A, interlocking shaft 12B, needle bar crank rod 13

Shaft hole 13B, inner cylinder 13C, square cam 14,

Cam hole 14A, take-up slide bearing 15, take-up lever 16,

Needle bar (17), female thread hole (17A), needle bar holder (18),

Needle bar holder shaft (18A), screw hole (18B), screw bolt (18C),

Swing table (19), needle bar upper metal (19A), needle bar lower metal (19B),

Cam guide groove 19C, sewing machine 20, counterweight 21,

Thread take-up lever crank 22, inner cylinder portion 22A, connecting shaft 23,

Shaft 23A, shaft 23B, crank rod 24,

Inner cylinder part 24A, inner cylinder part 24B, square cam 25,

Needle bar 26, needle bar holder 27, holder shaft 27A,

Needle attachment hole 28, sewing needle 29, upper louver holder bearing 40,

Upper louver guide metal 41, bushing member 41A, guide metal inner peripheral surface 41Aa,

Upper louver drive shaft 42, bearing 100, molded article 102,

Bearing inner surface 102A, fine part 102B, wear powder 102C

1 and 2, the sewing machine 10, which is one embodiment of the present invention, is described as follows.

In the conventional sewing machine having a lubrication device, since the lubrication is centered on the contact portions for sliding and rotational movement of the drive unit, the sewing machine 10 of the first embodiment is mainly described as the contact portion of the drive unit. In addition, the structure other than the drive unit may be applied to the structure of the sewing machine as in the prior art.

The drive unit with friction of the sewing machine 10 of the first embodiment is composed of a rotating shaft for sliding and rotating motion and a bearing for supporting the rotating shaft. In addition, the driving unit is the upper shaft 11 and the upper shaft 11, which rotates along the central axis, the upper shaft front metal 11A serving as a bearing of the upper shaft 11, and the upper and lower rotational movement of the upper shaft 11 Needle bar crank rod 13 converting to sliding motion, thread take-up lever 16 for supplying gastric thread to needle 1B, and thread take-up lever 16 are installed and become a bearing The bearing 15 of the lever 16, the needle bar 17, a needle-bar holder 18 mounted on the needle bar 17, a swing shaft 1D for oscillating motion, a needle bar Swing cam 19 to form upper metal 19A and needle bar lower metal 19B, and cam cam 14 which is guided in the cam guide groove 19C formed in the swing bar 19 and slides up and down. And a swing shaft metal 1C which is a bearing of the swing shaft 1D.

In addition, the bearing component which supports the axis | shaft which performs sliding motion and rotational motion among the said components has a structure like the bearing 100 (cylindrical type) shown, for example in FIG.

That is, the bearing 100 inserts and fixes the bushing-shaped molded article 102 formed of the above-described microscopic ceramics inside the metal cylindrical housing member 101 (outer cylinder portion) forming the outer shell. In addition, the bearing 100 serves as a bearing for supporting an axis (axially shaped parts not shown) in contact sliding or rotational motion with the bearing inner surface 102A of the bushing-shaped molded product 102. In addition, as shown in Fig. 5 (a), a plurality of fine-grained portions 102B are formed in the fine steel ceramics on the bearing inner surface 102A, which forms a friction surface in contact with the outer surface of the shaft (not shown). The wear powder 102C generated in the initial stage is filled into the fine portion 102B. Thus, the abrasive powder 102C acts as a solid lubricant when the shaft and the bearing inner surface 102A rub against each other, so that lubrication is achieved.

As shown in Figs. 1 and 2, the inner shaft portion 11A is mounted on the upper shaft front metal 11A, and a bushing formed of a microscopic ceramic is inserted / fixed on the inner surface of the inner cylinder portion 11Aa. . Accordingly, the upper shaft front metal 11A supports the upper shaft 11 to freely slide and rotate.

Counterweight 11B is fixed to one end of the upper shaft 11. The counterweight 11B has a coupling hole 11Ba, and the coupling hole 11Ba is adapted to fix the connecting shaft 12 for connecting the counterweight 11B and the needle bar crank rod 13. .

A cutting portion 12A is formed in the connecting shaft 12. The connecting shaft 12 is inserted into the insertion hole 11Ba of the counterweight 11B, and two screws formed in the counterweight 11B. The counterweight 11B and the connecting shaft 12 are integrally rotated by inserting the bolts 11Bc and 11Bc into the holes 11Bb and 11Bb and fastening them with screws.

An inner cylinder portion 13A is formed in the needle bar crank rod 13, and an interlocking shaft 12B formed in the connecting shaft 12 is coupled / supported in the inner cylinder portion 13A to freely slide and rotate. In addition, a shaft hole 13B is formed at the opposite side, and a shaft 15B formed at the thread take-up slide bearing 15 is coupled to the shaft hole 13B, and an inner cylinder 13C is formed at the lower end thereof. The needle bar holder shaft 18A formed on the needle bar holder 18 is coupled to the inner cylinder 13C to freely slide and rotate. Thus, in each of the inner cylinder portions 13A and 13C, bushings formed of microscopic ceramics are inserted / fixed, and the bushings are interlocking shafts 12B and needle bar holder shafts of the connecting shafts 12, respectively, which slide and rotate. It acts as a bearing to support 18A.

An inner cylinder portion 15A is mounted inside the thread take-up slide bearing 15, and a bearing shaft 15B is formed outside, and is inserted into the shaft hole 13B of the needle bar crank rod 13. Thus, the inner cylinder portion 15A of the thread take-up slide bearing 15 is coupled / fixed with a bushing formed of microscopic ceramics, and the thread take-up lever shaft 16A formed on the thread take-up lever 16 is the thread take-up slide bearing. The inner cylinder portion 15A of 15 is supported to freely slide and rotate.

The needle bar holder 18 is fixed to the needle bar 17 by engaging the screw bolt 18C in the screw hole 18B formed in the needle bar holder 18. In addition, a holder shaft 18A is formed in the needle bar holder 18, and the holder shaft 18A is inserted into an inner cylinder portion 13C formed in the needle bar crank rod 13.

An end portion of the needle bar holder shaft 18A inserted / passed into the inner cylinder portion 13C of the needle bar crank rod 13 is inserted / fixed into the cam hole 14A formed in the square cam 14.

In addition, the square cam 14 is guided along the cam guide groove 19C formed in the swinging base 19, and performs a sliding movement up and down. By doing so, the needle bar 17 is allowed to move up and down on the swinging base 19. The rectangular cam 14 is entirely formed of a fine ceramic, and both sides and the rear surface of the rectangular cam 14 perform sliding motion while rubbing in contact with each other along the cam guide groove 19C.

In addition, the square cam 14 does not necessarily need to be made entirely of microscopic ceramic material, but may form only both side surfaces and rear surfaces of the cam guide grooves 19C with frictional surfaces.

The rocking table 19 is composed of a needle bar upper metal 19A at an upper end, a needle bar lower metal 19B at a lower end, and a cam guide groove 19C for guiding the square cam 14. In addition, one end of the rocking shaft 1D is fixed to the rocking table 19, and the rocking table 19 and the rocking shaft 1D are made to oscillate integrally.

An inner cylinder portion 19Aa is installed in the needle bar upper metal 19A, and an inner cylinder portion 19Ba is installed in the needle bar lower metal 19B, and the inner cylinder portion 19Aa and the inner cylinder portion 19Ba are installed. Bushings formed of microscopic ceramics are inserted / fixed. In this way, the needle bar 17 is mounted in the needle bar upper metal 19A and the lower metal 19B to freely slide up and down.

In addition, a needle attachment port 1A for mounting the sewing needle 1B is installed at the lower end of the swinging base 19. A male screw shaft 1AA is formed on the upper surface of the needle attachment port 1A, and is screwed to the female screw hole 17A formed at the lower end of the needle bar 17. Therefore, the needle is inserted from below the needle attachment hole 1A and the two screw bolts 1AC are inserted / fixed into the screw holes 1AB on both sides, respectively.

An inner cylinder portion 1CA is mounted on the oscillating shaft metal 1C, and a bushing formed of a microscopic ceramic is engaged / fixed in the inner cylinder portion 1CA. Therefore, the rocking shaft metal 1C is a bearing that supports the sliding motion of the rocking shaft 1D.

In the general manufacturing method, the mild steel ceramics have different hardness depending on the firing temperature during manufacturing. Therefore, the hardness of the microscopic ceramics used in the present embodiment is set in the range of about 40 to 150 (MPa) Vickers hardness (Hv) that can be applied to the site of the sliding or rotating movement of the sewing machine.

Likewise, rice bran ceramic, so the porosity is changed according to the sintering temperature, it is possible to adjust the density. Therefore, the density in the example part of this embodiment of the sewing machine about ^{1.08 x 10 3 ~ 2.0 x 10} 3 (kg / m 3) It is set to a range. Therefore, compared with copper, about 5 to 8 times can be reduced in weight, and compared with aluminum, about 1 to 3 times can be reduced in weight.

Therefore, as described above, when the micro-strength ceramics are used as bearings, the weight can be reduced. Therefore, the surface pressure that causes the shaft and bearing to contact / friction is reduced, the PV value is reduced, and the wear resistance and the adhesion resistance Can contribute to improvement.

In addition, when used in contact portions under high PV value conditions, it is also advantageous to impregnate a lubricant such as grease into the pores. In this case, wear resistance and adhesive resistance can be further improved. In addition, when the porosity is increased, that is, when the lubricant is impregnated in the fine steel ceramics produced with a low density, wear resistance and adhesion resistance can be improved.

On the other hand, the fine steel ceramics can be set within the range of 0.06 ~ 0.18 by adjusting the firing temperature in the manufacturing process.

In addition, the microscopic ceramics may be set in the range of 50 to 100 MPa by adjusting the firing temperature in the manufacturing process.

On the other hand, in the first embodiment of the present invention, the manufacturing method of the parts of the sewing machine 10 is manufactured by the same method as the conventional method except that the parts that form the friction surface of the contact portion of each component of the drive unit to be produced by the mild steel ceramics can do.

That is, inner cylinder parts 11Aa and 13A serving as bearings of the upper shaft front metal 11A, the needle bar crank rod 13, the thread take-up slide bearing 15, the swinging table 19, the swing shaft metal 1C, and the like. Bushings formed of microscopic ceramics manufactured by the above-described manufacturing method are applied to the friction surface portion of the inner surface of 13C, 15A, 19Aa, 19Ba, 1CA) by using an adhesive or mechanical fastening method (for example, screwing). Insert / Fix

In addition, the square cam 14 may be molded in the form of fine ceramics. Alternatively, the member formed of the microscopic ceramics on the part forming the friction surface may be fixed by using a mechanical fastening method such as an adhesive or a screw.

Then, by using each of the constituent members formed on the friction surface of the fine ceramics, the sewing machine 10 can be assembled and manufactured by a conventional method.

In the sewing machine 10 according to the first example of the embodiment of the present invention, the contact portion between the bearing portion provided on the upper shaft front metal 11A, the needle bar crank rod 13, or the like, the square cam 14 or the like / The friction surface part to be rubbed is formed of a mild steel ceramic having a small coefficient of friction. In addition, since the back surface of the friction surface is formed by a plurality of fine hairs due to the pores, it is possible to accommodate the wear powder acting as a solid lubricant. Therefore, the amount of wear can be reduced, and lubrication of the sewing machine 10 can be achieved.

In addition, since lubricating oil is not required, it is not necessary to install a lubrication device for supplying lubricating oil to the sewing machine, thereby making it possible to reduce the weight of the sewing machine. In addition, it is possible to further reduce the weight by using a small density of fine ceramics.

In particular, in the above embodiment, since the entire swing table 19 is formed of a microscopic ceramic, the PV value applied to the swing shaft metal 1C supporting the swing shaft 1D to which the swing table 19 is attached is determined. The wear resistance of the oscillating shaft metal 1C can be improved. In addition, since the inertial force acting on the rocking motion of the rocking table 19 can be reduced, the needle bar can be vibrated accurately, thus forming a clean sewing seam.

In addition, since the lubrication device is not necessary, the manufacturing cost of the sewing machine can be reduced because the number of parts of the sewing machine and the manufacturing process of the sewing machine can be reduced.

Further, as a modification of the present embodiment, it can also be applied to the drive unit of the sewing machine 20 having the structure shown in FIG.

3, the driving portion of the counterweight 21, the thread take-up lever crank 22, the counterweight 21 and the connecting shaft 23 for connecting the thread take-up lever crank 22 and the crank rod 24, rotational movement Crank rod 24 for converting the vertical motion into a vertical, a rectangular cam 25 is coupled / fixed to the crank rod 24, a needle bar 26 for supporting the sewing needle 29 in the lower end, the needle bar 26 ) And a needle bar holder 27 connecting the crank rod 24 to the lower end of the needle bar 26.

When the drive unit of the sewing machine 20 operates, between the inner circumferential surface of the inner cylinder portion 22A formed on the thread take-up lever crank 22 and the outer circumferential surface of the shaft 23A formed on the connecting shaft 23, the crank rod ( The inner circumferential surface of the inner cylinder portion 24B formed on the crank rod 24 and the needle bar holder 27 between the inner circumferential surface of the inner cylinder portion 24A formed on the 24 and the outer circumferential surface of the shaft 23B formed on the connecting shaft 23. The shaft and the bearing in contact with each other between the outer circumferential surface of the holder shaft 27A formed on the circumferential surface friction with each other.

Therefore, by inserting / fixing a bushing member formed of microscopic ceramics on the inner circumferential surfaces of the inner cylinder portions 22A, 24A, and 24B, lubrication can be achieved when the driving unit of the sewing machine 20 operates.

In addition, when the square cam 25 makes contact / friction movement with other parts as in the first embodiment, a member formed of microscopic ceramics may be attached / fixed to the friction surface portion of the square cam 25.

Further, as shown in FIG. 4, the present invention can also be applied to an upper louver holder bearing 40.

The upper louver holder bearing 40, as shown in Figure 4, the upper louver guide for freely supporting the sliding and rotational movement of the upper louver drive shaft 42 and the upper louver drive shaft 42 for driving the upper louver It is comprised by the metal 41.

At this time, the outer surface of the upper louver drive shaft 42 and the inner circumferential surface 41Aa of the upper louver guide metal 41 which perform sliding and rotational movements are in contact with each other / friction. Accordingly, the oil-free can be achieved by inserting / fixing the bushing member 41A formed of the microscopic ceramics on the inner circumferential surface of the upper louver guide metal 41.

In addition, the upper louver guide metal 41 is mounted to rotate freely on the upper louver guide support (not shown). Thus, the outer surface 41a of the upper louver guide metal 41 and the louver guide support (not shown) come into contact with each other / friction. Therefore, a structure for attaching / fixing the member formed of the microscopic ceramics in accordance with the shape of the outer circumferential surface of the upper louver guide metal 41 is also possible.

For example, as shown in Fig. 5 (b), a member (housing member 101) forming an outer shell is formed by using a component (bearing 100) of the contact portion using a material different from the hard porous carbon material. A structure for fixing the member (molded product 102) formed of a hard porous carbon material to the friction surface portion of the outer member is also possible. In this case, if a material different from the hard porous carbon material is used, for example, a metal material or the like, mechanical strength and durability can be imparted to the parts to be contacted / frictiond.

It is obvious that the rigid porous carbon material can be applied to sewing machine parts other than the description of the above embodiment.

In the sewing machine described in claim 1, since the portion forming the friction surface is formed of a hard porous carbon material having a small coefficient of friction, it is possible to achieve lubrication of the contact portion of the sewing machine.

In addition, since the lubricating oil or the like does not need the contact portion, the weight can be reduced. In addition, for example, a hard porous carbon material having a smaller density than that of a metal material is used, thereby contributing to weight reduction.

In addition, since the lubrication device is not necessary, the number of parts of the sewing machine can be reduced, thereby reducing the sewing machine manufacturing process, thereby reducing the production cost.

In the sewing machine described in claim 2, since the friction surface is formed of a hard porous carbon material, when the axial portion rotates in contact with the inner circumferential surface of the annular portion or makes a sliding movement in the axial direction, Similarly, lubrication of shafts and bearings can be achieved.

In the sewing machine described in claim 3, the wear component generated in the initial wear stage is introduced into a plurality of fine parts formed on the friction surface, so that the wear component reduces the friction coefficient when the parts are contacted / frictioned. Because it shows self-lubricating activity, it becomes possible to make lubrication free.

Claims (3)

In the movable device of the sewing machine in which the two parts in contact with each other relatively sliding and rotational movement, At least one of the contact surfaces of the parts is formed by a hard porous carbon material. The method of claim 1, One of the two parts has a metal annular part, the other part is formed as an axial part to be inserted into the annular part, and the contact surface of at least one part is formed of the hard porous carbon material. Movable device of the sewing machine. The method according to claim 1 or 2, And the contact surface formed of the hard porous carbon material has a plurality of fine cuts based on the pores of the hard porous carbon material.